1. Field of the Invention
The present invention relates to a magnetic composite sheet and an electromagnetic induction module capable of efficiently controlling a flow of a magnetic field.
2. Description of the Related Art
Research into a system for contactlessly transmitting power in order to charge the power in a secondary battery embedded in a portable terminal, or the like, has recently been conducted.
A contactless power transmission device generally includes a contactless power transmitter transmitting power and a contactless power receiver receiving and storing the power therein.
The contactless power transmission device transmits and receives the power using electromagnetic induction. To this end, respective interior portions of the contactless power transmitter and the contactless power receiver are provided with coils.
A contactless power receiver configured of a circuit part and a coil part may be attached to a cellular phone case or an additional accessory in a cradle to implement a function thereof.
In describing an operational principle of the contactless power transmission device, commercially available alternating current (AC) power from external power supply is input to a power supply unit of the contactless power transmitter.
The input commercially available AC power is converted into direct current (DC) power by a power conversion unit, is then again converted into an AC voltage having a specific frequency, and is then provided to the contactless power transmitter.
When the AC voltage is applied to the coil part of the contactless power transmitter, a magnetic field around the coil part changes.
As the magnetic field of the coil part of the contactless power receiver disposed to be adjacent to the contactless power transmitter changes, the coil part of the contactless power receiver outputs power to charge the secondary battery therewith.
In the contactless power transmission device, a magnetic sheet is positioned between a radio frequency (RF) antenna and a metal battery in order to increase a communications distance.
According to the related art, a flexible ferrite substrate is manufactured by allowing the ferrite sheet to have at least one continuous U or V shaped groove before being sintered and laminating a ferrite substrate between an adhesive film and a polyethylene terephthalate (PET) film after sintering the ferrite sheet.
Currently, in order to commercialize contactless power receivers, the development of a high efficiency contactless power transmission device has been demanded.
The following Related Art Document (Patent Document 1) discloses a magnetic sheet including magnetic pieces, but fails to disclose that magnetic pieces have different sizes and shapes.